A comparison of pulmonary function in bronchial asthma and chronic obstructive bronchitis

Abstract
The dynamic and static lung volumes, arterial blood-gas tensions, and single-breath carbonmonoxide transfer factor have been compared in 72 asthmatic and 45 bronchitic patients with airways obstruction of comparable severity to determine which measurements might be used to discriminate between the two diseases. The forced vital capacity, total lung capacity, arterial carbon-dioxide tension, and transfer factor were useful in this respect. Thus, in a patient with airways obstruction the finding of a low% predicted FVC (2 is most compatible with a diagnosis of bronchial asthma.